Cation channel with high affinity for sodium, which is gated by extracellular protons and inhibited by the diuretic amiloride. Generates a biphasic current with a fast inactivating and a slow sustained phase. In sensory neurons is proposed to mediate the pain induced by acidosis that occurs in ischemic, damaged or inflamed tissue. May be involved in hyperalgesia. May play a role in mechanoreception. Heteromeric channel assembly seems to modulate channel properties.

This gene encodes a member of the degenerin/epithelial sodium channel (DEG/ENaC) superfamily. The members of this family are amiloride-sensitive sodium channels that contain intracellular N and C termini, two hydrophobic transmembrane regions, and a large extracellular loop, which has many cysteine residues with conserved spacing. The member encoded by this gene is an acid sensor and may play an important role in the detection of lasting pH changes. In addition, a heteromeric association between this member and acid-sensing (proton-gated) ion channel 2 has been observed as proton-gated channels sensitive to gadolinium. Alternatively spliced transcript variants have been described. [provided by RefSeq, Feb 2012]

ASIC3 is able to sense the extracellular pH in both directions and to dynamically adapt its activity between pH 5.0 and 8.0, playing a role in fine tuning neuronal membrane potentials and neuron sensitization in various pH environments.